Spirometry
Spirometry is the most common pulmonary function test. You breathe into a mouthpiece connected to a device called a spirometer, which measures how much air you can exhale and how quickly. It helps diagnose and monitor asthma, COPD and restrictive lung patterns, supports assessment in pulmonary fibrosis or interstitial lung disease, and may be combined with diffusion testing.
Medically reviewed by the Florence Healthcare medical team · Last reviewed June 2026
Overview
Spirometry measures lung function by recording the volume and speed of the air you breathe out. After taking a full breath in, you seal your lips around a mouthpiece and blow out as hard and as long as you can, usually repeating the effort a few times for an accurate reading. The two key results are FEV1 (the air exhaled in the first second) and FVC (the total air exhaled); their ratio helps distinguish obstructive disease such as asthma or COPD from restrictive patterns. It is also used in patients with suspected lung hardening, pulmonary fibrosis or other interstitial lung diseases, and can be complemented by a diffusion test to assess how well oxygen passes from the lungs into the blood. Sometimes the test is repeated after an inhaled bronchodilator to see whether your airways open up.
For patients travelling from abroad, spirometry is often part of a wider chest assessment combined with imaging and a specialist consultation. A coordinator can arrange the test, the pulmonology review and any follow-up within a single visit, and our specialists can review prior breathing-test results and CT scans remotely before you travel to plan your care efficiently.
Who is a candidate?
- People with unexplained breathlessness, a persistent cough or wheeze
- Patients with known or suspected asthma or COPD, to confirm the diagnosis and grade severity
- Patients with suspected pulmonary fibrosis, interstitial lung disease or lung hardening who may also need diffusion testing
- Smokers or former smokers being screened for early airflow obstruction
- Anyone being assessed before surgery or anesthesia where lung function matters
- Patients monitoring a chronic lung condition or their response to treatment over time
What happens
- 1
Before the test
You may be asked to avoid certain inhalers, heavy meals, smoking and vigorous exercise for a few hours beforehand. Wear loose clothing that does not restrict your chest, and bring a list of your current medications.
- 2
Preparation in the lab
A technician explains the procedure, fits a soft nose clip so all the air goes through your mouth, and shows you exactly how to breathe into the mouthpiece for the best result.
- 3
Performing the breathing effort
You take the deepest breath you can, then blow out as hard and as long as possible into the mouthpiece. The effort is repeated several times to obtain consistent, reliable readings.
- 4
Bronchodilator response (if needed)
If reversibility needs checking, you are given an inhaled bronchodilator and the test is repeated after about 15 minutes to see whether your airways open up.
- 5
Results and next steps
A pulmonologist interprets your numbers against predicted values for your age, height, sex and ethnicity, explains what they mean, and recommends treatment or further tests the same day.
Benefits
- Quick, painless and non-invasive, with no needles, radiation or recovery time
- Helps confirm a diagnosis of asthma, COPD or other airflow problems
- Grades the severity of lung disease and tracks how it changes over time
- Shows whether airways respond to bronchodilator medication
- Supports safe planning before surgery and anesthesia
- Provides objective results the same day to guide treatment decisions
Risks & considerations
- Very safe overall, with no lasting side effects
- The forced breathing can briefly cause lightheadedness, coughing or shortness of breath
- Not advised soon after a heart attack, recent eye, chest or abdominal surgery, or certain conditions raising chest pressure
- Results depend on effort and technique, so a poorly performed test may need to be repeated
- Active respiratory infection may temporarily affect accuracy and require rescheduling
Where it is performed
This procedure is performed by our Chest Diseases Department.
Learn more before you decide
Provider-reviewed guides on the related conditions, symptoms and tests in our Health Library.
Spirometry — frequently asked questions
No. Spirometry is painless and non-invasive. You simply breathe into a mouthpiece. The forceful breaths can make you feel briefly lightheaded or make you cough, but this passes quickly and there is no recovery time.
Wear loose clothing, avoid smoking, large meals and vigorous exercise for a few hours beforehand, and tell the team about your inhalers, as some may be paused before the test. Bring a list of your current medications.
The test itself takes about 15 to 30 minutes, and a pulmonologist usually interprets and explains the results the same day, often during the same visit as your consultation.
Yes. Our pulmonology team can review your previous spirometry results, CT scans and reports remotely before you arrive. This confirms what further testing is needed and lets us plan your visit and any treatment efficiently.
Cost depends on whether spirometry is performed alone or as part of a wider chest assessment with imaging and a consultation. We provide a clear, personalized estimate in advance so you know what is included before you commit.
Often a single test is enough for diagnosis. If you are being monitored for a chronic lung condition or are starting new treatment, your specialist may repeat spirometry periodically to track how your lungs are responding.
Related treatments
Considering spirometry?
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